The nitty-gritty of design is drawing and, today, it is largely CAD based, even though you may start with some preliminary hand-drawn work.

One of the worst things that can happen in CAD is not knowing how to do something really simple, like changing a line!

When I selected CAD software initially in my practice, I chose VectorWorks (then called something else). Amazingly, that is nearly twenty years ago now but upgrades can be challenging, not to mention unexpected changes in your drawing.